Pyrotinib Treatment In Patients With HER2-Positive Metastatic Breast Cancer:A Real-World,Multicenter Analysis

ObjectivePatients with HER2-positive(HER2+)metastatic breast cancer(MBC)have poor prognoses.Pyrotinib has shown promising antitumor activity in MBC to improve PFS.However,findings based on real-world data to analyze whether pyrotinib affects overall survival(OS)remain scarce.MethodsIn this retrospective study,168 patients who received pyrotinib treatment for HER2-positive metastatic breast cancer(MBC)in Hunan Province from June 2018 to August 2019 were included.PFS,OS,clinical benefit rate(CBR),overall response rate(ORR)and drug-related adverse events(AEs)were analyzed.Ninety-four patients who received pyrotinib as a third-or higher-line treatment for HER2-positive MBC were included in this retrospective study.Propensity score matching(PSM)and inverse probability of treatment weighting(IPTW)analysis were implemented to balance important patient characteristics between groups.Resultspyrotinib treatment led to a median PFS time of 8.00 months and a median OS of 19.07 months in the 168 participants.In the 39 patients with BM,the median PFS and OS were 8.67 and 13.93 months,respectively.The surgery/radiation(S/R)group of patients with BM had prolonged survival(PFS: 9.97 vs.7.73 months P = 0.19;OS: 20.67 vs.12.43 months P = 0.021)compared with the no surgery/no radiation group(NS/NR).The CBR was 58.6%(S/R)vs.41.4%(NS/NR),while the ORR was 24.1%(S/R)vs.31.0%(NS/NR).Among the ninety-four patients who received pyrotinib as a third or higher-line treatment,30(31.9%)patients were pretreated with lapatinib and subsequently received pyrotinib as an antiHER2 treatment,and 64(68.1%)patients did not receive this treatment.The OS and PFS indicated a beneficial trend in lapatinib-naive group compared to lapatinib-treated group in either the original cohort(PFS: 9.02 vs 6.36 months,p = 0.05;OS: 20.73 vs 14.35 months,p = 0.08)or the PSM(PFS: 9.02 vs 6.08 months,p = 0.07;OS: 19.07 vs 18.00 months,p = 0.61)or IPTW(PFS: 9.90 vs 6.17 months,p = 0.05;OS: 19.53 vs 15.10 months,p = 0.08)cohorts.Diarrhea occurred in 98.2% of participants(in any grade)and 19.6% in grade 3–4 AEs.ConclusionPyrotinib is highly beneficial to higher-line HER2-positive MBC patients,especially in lapatinib-naive patients.pyrotinib shows promise as a novel pan-HER2 tyrosine kinase inhibitor(TKI)for the treatment of BM and should be evaluated further.Surgical or radiotherapy in combination with pyrotinib was found to statistically improve OS in our cohort.